Carburetor



Oct. 4, 1932. F H. sMlTH 1,880,990

CARBURETOR Filed April 18. 195o kif;

i An important object of thepresent inven- Patented Oct. 4, 1932 PATENT @FFE .FREDERICK VH'GrI-I SMITH, OF NOTTINGHAM, ENGLAND CARBURETOR This invention' relates-to carburetors such as are employed for producing an eXplosive mixture fo-ruse in an internal 'combustion engine.

tion is to provide a carburetorl of simple construction and operationwhich will produce under all conditions of working a more thori. l. ough and eective vapourization or atomization vof the fuel and ysecure a more complete mixing of the fuel and air'than is possible with known or proposed carburetors.

A Vfurther object of the present invention is to provide a carburetor giving the maximum economy under all conditions of service but which is adaptable to vproduce a rich mixture when the engine is running at slow speeds in order that starting may be facilitated.

Further objects are attained by the novel arrangements and construction desc-ribed below with reference to the accompanying drawing.

` One feature consists of the provision of means wherebyliquid fuel is supplied to a porous or perforated member independently of suction or vacuum effort.

In one method of attaining this end the fuel is fed to a rotary perforated disc by capillary r or centrifugal action' or jby a combined centrifugal and capillary action, the arrangement being that at slow speeds the disc is fedin the main by capillary action and at high speeds mainly by centrifugal action.

In order more fully to understand'thepr'esent invention reference-.isdirected to the accompanying drawing illustrating a preferred form of theinvention and wherein c Fig. lis a sectional view of a carburetor.

',-c Fig. 2 is a perspective view of the fluid contro-lling valve.A

Figs. 8 and 4 are detail views showing modified .forms of petrol withdrawing elements.

In the drawing a gauze or like perforated disc 8 yis located with its axis of rotation vertical, andthe petrol or the like is fed to the dis'cfrom a :float chamber 82 disposed beneath i said disc, from which float chamber petrol'is withdrawnby the combined centrifugal and frictionalaction (of a member 83 operating therein and rotating in' unison with the disc'.

:Applicare-ibn med April 1s, 1930, serial No. 445,404, and in canada April 29, 1929.

The driving spindle 7 for the disc 8 `is rotatably borne within a suitable boss 85 forming an integral portion of or extending from the throttle chamber 86, a grease cup or equivalent means of lubrication 87 being provided on said boss 85. The spindle 7 is also rotatable within a sleeve 88 extending diametrically across the interior of the throttle chamber 86, and on the extremity of said spindle is fixed by pin or other means the petrol withdrawing member 88 which may comprise a metal sleeve covered eXteriorly with felt or equivalent material which in one arrangement may be closely adhered to the sleeve by shellac or other substance insoluble in petrol, the longitudinal edges of the felt being pressed into a slot in the sleeve.

`This member 88 lits closely within and is rotatable within an internally screw threaded sleeve 89 which latter has at its lower end an inverted dish-shaped portion 90 which rests upon the base of the float chamber 82. Perforations 90a are provided in the dish portion 90 through which petrol may flow into the float chamber above same f and act upon the float 91.

92 is the petrol inlet connection, the petrol entering thereat flowing through passage 98 and removably mounted gauze or like filter elements 94 to a duct 95, the opening of which duct is controlled to the lower part of the float chamber by means of a vertically disposed needle valve'96 carried by a centrally pivoted lever element 97, said lever also carrying the float 91 which is preferably of annular formation encircling the internally screw-threaded sleeve 89. The pivot 97a for the float and valve lever 97 is removably carried'within a slot 98 in a part of the float chamber wall extending laterally into the float chamber, said pivot comprising a taperedv pin which is readily removable so as to permit quick insertion and removal of float and valve.

The petrol filter elements 94 may be installed within an annular cavity in a fitting 99 which embodies the petrol inlet connection 92 and duct 93, the gauze being advantageously retained in position by a split spring wire ring 100, and the fitting 99 being ing the disc 8 is in this arrangement formed between an upper horizontal flange 89a of theV float chamber and a circular recessed portion 86a on the underside of the throttle chamber, one or more air inlet apertures 103 kto the disc chamber Q being formed through the flange 82a, and a series of lines of small perforations 9 being provided in the base of the throttle chamber immediately beneath the position adapted to'be occupied by the throttle valve 104.A fThis throttle valve ad-` vantageously comprises a split sleeve which is sprung into close engagement with the interior of the chamber 86,'sa1d sleeve valve `having in the wall thereof a port 105 preferably of triangular formation,and also one or more small perforations 106 (see Figure 2) the purpose of which-will be described hereinafter.

The rotationfof the sleeve throttle 104 is effected from a throttle lever 107 through the medium of vpins 108 projecting laterally from the throttle lever spindle 109 and coacting with diametrically opposed slots 110 in the valve, said slots being open ended so as to permit of the ready removal of the valve operating means from the valve as and when required.

The valve spindle 109 is preferably accommodated within a sleeve 111 formed integrally with a cover plate 112 of the throttle chamber, said cover platehaving therein one or more air inlet apertures 113 adapted to be opened and closed at will by the rotation of a suitable perforated disc 114 which rotates with the valve spindle.

In operation, when the engine to which i the carburetor is fitted is started up, the

throttle valve is rotated first tobring the small perforation or perforations 106 in said valve into registerV with the innermost per- Y foration or perforations 9 in the' valvechamber, that is to say, the perforation nearest the centre of rotation of the disc 8.V While in this position petrol is withdrawn from the float chamber by capillary action up the felt or the like on the withdrawal member 83, such petrol being fed to the central portion of the dis-c 8 and spread evenly thereon by centrifugal action, an annular bevelled ring 115v on the underside of the disc ensuring the eective spreading of the petrol .over the gauze. The suction effect produced by the engine causes air to enter at one or more openings 103 beneath the'disc 8, such air bursting they petrol in said disc and mixing same to enter the throttle chamber through Lthe uncovered perforations 9 and valve open- When the engine isf running at higher speeds the rotating member 83 serves to drag round the part of the liquid in contact therewith so that it exerts a rotary motion and is thereby caused to move upwardly in the spiral grooves in the sleeve 89. In addition, on accountof the rapid whirling motion of the columnof liquid the sameisforced by centrifugal action towards the base of the grooves, this assisting in holding the liquid therein. When the liquid reaches the top of the groove it is evenly spread over the rotating disc 8 and is drawn, mixed with air, into the throttle chamber, through the perforation or perforations`9 locatedffa'rthest from the centre of the carburetor, this being effected by causing the small perforation or perforations 106 to pass out of register with perforations 109 and by gradually bringing the triangular port 105 into Vregister with the perforations 9. The continued rotation of the throttle gradually uncovers in succesysion all of the perforations 9 from the outermost to the innermost. In this way it will be appreciated that the fuel is drawn vfirst from the part nearest the centre when starting up then immediately afterwards drawn from the part farthest removed from the centre, the petrol film being thickest when operating at slow speeds and becoming thinner as the speed increases. Thus easy starting up is assured and high efciency with petrol economy providedl when the speed` of theengine increases.

The internal thread' on the member 89 is so 10 designed as to ensure effective drawing `up of the petrol Valong same by rotation of the internal member 83 frictionally operating within said member while restricting -the withdrawal to predetermined limits when operating at high speeds.

From the above it will be seenthat during the starting uprthe petrol is fed by capillary action while as the speed increases such feed# ing is effected by centrifugal force, thus posin.0 tive control is effected irrespective ofv suction and at no time in thev operation of the carburetor is there any excess of petrol feed. Y Additionally the petrol supplied is independent'of any suction or vacuum forces. 115

The petrol supplied from V the float chamber to the disc 8 may be controlled to a consider-v able extent by a'disc 8a constituting vthe central boss of said disc `8 andrevolving with same, said central disc 8a extending over the 120 top of the internally threaded member 89 within which the rotating member 83'rotates. The central disc 8a may have associated there with one or more washers of feltV or equivalent material andlthej arrangement may bev such that the member`89 may be'adjusted'to'- wards or away from said central disc. It will thus beV appreciated that if' the upper edge of member 89v is Vinclose proximity to Y disc 8a only acomparatively small quantity 130 of petrol can be fed to the perforated disc 8. Similarly, if one or more washers are associated with the central disc 8a and member 89 is caused to compress same, the passage of petrol is thereby restricted.

A baflier plate of any suitable material may be employed at the top of the float chamber for preventing undue supply of petrol to the disc 8 duev to jolting or -abnormal angular disposition of said float chamber. This baffler may comprise a perforated plate havin felt or the like on either vor both sides thereo Although the method of controlling the fuel inlets 9 just previously described has been found to be effective in operation, it is to be understood that such inlets may be controlled in any sequence. It is, however, important that when operating at comparatively slow speeds the outer openings 9, i. e. those farthest removed from the centre, are in operation so as to assure slow speed economy.

If desired, the rotating petrol withdrawal member may be constructed in the manner as shown at 83a in Figure 3 wherein the felt or other absorbent friction material is in the form of longitudinally extending strips 120 closely enclosed within parallelly disposed slots along the member 83a. c

In a modilied arrangement the petrol withdrawal member may `be of hollow conical formation, as shown at 116 in Figure 4f, said member having at its pointed end a plug or cap 117 with small central perforation through which the petrol is drawn. Normaly, ly the petrol is maintained within the member 116 at a suitable height, say approximately half-way up, and in starting up the engine such petrol is fed by capillary action to the disc by felt or other absorbent lining 118. As the speed of rotation increases the level of petrol in the member is gradually lowered by reason of the fact thatfthe increased centrifugal force within the cone causes the petrol to be withdrawn faster than the small inlet in nozzle 117 will permit ingress of petrol. Thus by suitably determining the size of the inlet aperture the amount of liquid gaining access tothe cone can at all times be caused to b-alance the amount withdrawn and excess ofpetrol feed is effectively prevented. By experiment it has been found that an effective angle of taper of the cone member is approximately 30. When employing a conical withdrawal member such as last` previously described anyv suitable means. are provided for preventing upward drawing or feeding of petrol on the exterior of the member. f

If desireda cap with small central aperture may be provided at thelower extremity of withdrawal. member 83 such as shown in Figures 1 and 3 for governing the amount of petrol fed tothe internal screw 89.

It is understood that the series of perforations 9 in Figure 1 may be replaced by a narrow elongated slot.

The perforations may, instead of being arranged in a straight line, be composed of a plurality of lines or rows of perforations, the perforations of each row being disposed relatively to each other and to the port in the rotating throttle member so that after opening the first perforation each succeeding perforation commences to open before the next preceding perforation is fully opened. A more uniform supply of burst filaments during the uncovering of said perforations is thus ensured.

Instead of producing the petrol film upon or in a disc or the like as before described, same may be formed in a restricted space between said disc and an adjacent surface.

I claim 1. In a carburetor, a rotary disc incorporating perforated material, an air inlet through which air is drawn to penetrate the film on said disc, fuel mixture withdrawal apertures connecting with a mixing chamber, a displaceable throttle valve interiorly of said mixing chamber for controlling the amount of fuel withdrawn from said disc and means for feeding liquid fuel to said disc by capillary and by centrifugal action.

2. In a carburetor, a rotary disc incorporating perforated material, capillary and centrifugally acting means for supplying liquid fuel to said disc, an air inlet through which air passes to penetrate the film on the disc, a series of withdrawal apertures thro-ugh which fuel mixture may be drawn from said disc and a displaceable throttle valve for progressively opening said series of apertures.

3. In a carburetor, a rotary disc incorporating perforated material, means for supplying liquid fuel thereto independently of suction or vacuum effort, means whereby the amount of petrol passed to said disc is controlled by the adjustment of the fuel supplying means relatively to said disc and mea-ns for withdrawing fuel mixture from said disc.

4. In a carburetor, a rotary disc incorporating perforated material, means for feedingv liquid fuel to said disc near the axis of rotation to produce a film of fuel on the disc, a petrol withdrawing member operating by centrifugal and by capillary action, vmeans whereby the adjustment of ysaid petrol withdrawing means relatively to the rotary disc controls the amount of petrol supplied to said disc, inlet means through which air may passto penetrate the film on the disc and a series of apertures through which the mixture generated may be drawn from such disc.

5. In a carburetor, a rotary disc .incorporating perforated material, means for feeding liquid fuel thereto near the axis of rotation to produce a film of fuel on the disc,

petrol withdrawing means functioning by centrifugal and by capillary action to feed fuel to such disc, means whereby the adjustment of said petrol withdrawing member relatively to said disccontrols the amount of fuel suppliedtliereto, an airinlet aperture through which -air vmay passte burst or penetrate the film on the disc, a series of fuel mixture `withdrawal lapertures opening into a mixing chamber, adisplaceable throttle valve interiorly ofsaid mixing chamber adapted progressivelyto uncover said series of apertures and'additional air apertures to said `mixing chamber controlled inunison with said throttle valve. l z. o

6. Ina carburetor, a rotary disc incorporatingperfor'ated material, a liquid fuel chamber, an internally grooved member, a ineinber rotatable in unison with the disc and arl' vrangedA interiorly of said internally grooved member whereby liquid is raised jup said grooved member, means whereby such` liquid is distributed over said rotary disc and means for withdrawing fuel mixture from said disc. i

7. vIn a carburetor, a rotary disc incorporating perforated material-arranged on a vertical axis, a liquid fuel chamber, yan vinternally grooved member dipping into said fuel chamber, an element carried on the under side of said disc and coacting with said grooved member whereby kliquid mayv be raised from said fuel chamber and distributed over the rotary disc, means for adjusting Y 555? said withdrawal-element relatively to the M tary disc for regulating the amount of fuel supplied to said disc, air inlet apertures, fuel `mixture withdrawal apertures and means adjustmenty of said felt covered element relatively yto said rotary disc regulates the amount:

of fuel supplied to suchV disc/and ymeans for `withdrawing fuel mixture from said disc.A

f V9., In a; carburetor, a disc rotatable on a vertical axis and incorporating perforated material, aliquid fuel chamber, an internal- 'esi ly grooved sleeve. dipping into said fuel chamber, a felt coveredY withdrawal element carriedon the under face of said disc and rotat! able interiorly of said grooved sleeve where- L kby fuelv may be fed'by capillary action to the disc at Qlowspeeds and by centrifugal action at high speeds, afpetrol filter element below said fuel chamber, means forsupplyingpetrol thereto, float control means for controlling admission of petrol to said fuel chamber and maintaining a constant level therein, a series of fuel withdrawal apertures for the mixture generated by the disc and means for progressively openingsaid .series of apertures.

10. ln a carburetor, a disc rotatable on a vertical axis and incorporating perforated material, a lliquid fuel chamber, an internally grooved `sleeve dipping into said fuel chainber, a withdrawal'element incorporating inset absorbent strips and rotatable interiorly of said sleeve wherebyfuel may be fed by capillary action to the disc V`at low speeds and by centrifugal action at Vhigh speeds, means whereby the adjustment of said withdrawal element relatively to said rotary disc regulates the amount of fuel supplied to the disc and means for withdrawing fuel mixture from the disc.

ll. In a carburetor, `a disc rotatable on a vertical axis, a conedwithdrawal member on the underside of said disc, an aperture at the depending pointe-d end of said withdrawal member, absorbent material interiorly'of said coned member, a fuel supply chamber in to which said withdrawal member dips, Vmeans whereby the liquidV fuel raised by said v absorbent material at low speeds maybe distributed c'ver the rotary disc, means whereby at higher speedsthe liquid may be raised'by centrifugal action, means forv admitting air toA penetrate the iilmon the disc andV means for removing fuel mixture'therefrom.

f l2. in a carburetor, a disc incorporating perforated material, meansfor rotating said v disc on a vertical axis, a fuel supply chamber below' said disc, a liquid withdrawal member mounted below saiddisc and rotating therewith, capillary means 'for feeding fuel from said fuel supply chamber to'near the centre ofthe rotary disc 'from whence the fuelis spread oversaid disc asfa film,centrifugally operating means serving also to raise fuel from said chamber to said rotary disc and means for drawing air throughthefilm on said disc to produce avaporizedmixture.

13. In acarburetor, adisc incorporating perforated material, means for rotating said disc on a vertical axis, a fuel lsupply chamber below said disc, capillary means functioning at lower speeds to feed fuel fromisaid fuel chamber to near the centre of rotation of said disc, means operating at higher-engine speeds to raise liquid by centrifugal 'action from said fuel supplyk chamber to near the centre of said rotating disc and means for drawing a stream of air through the film of lliquid produced on said disc.

' FREDERICK HUGH SMITH.`

sie 

